AbstractThe distributions of mean velocity and flow area have been determined on the boundary between the intake valve and cylinder head. Steady flow measurements were made using hot wire anemometry in this initial study of the influence of induction system geometry on piston engine combustion via its effects on in-cylinder fluid mechanics. Data were obtainedfor three different induction systems known to produce significantly different combustionrates with the same combustion chamber. The distribution of flow variables at thevalve was found to differ markedly between the three induction systems investigated. The combustion rates with these induction systems correlated with the kinetic energy and angular momentum fluxes measured at the valve, as well as the isentropic flow velocity computed fromthe measured pressure drop.